Apparatus for strapping packages



June 13, 1967 ET R 3,324,789

APPARATUS FOR STRAPPING PACKAGES Filed Jan. 5, 1966 6 sheets sheet lINVENTOR HUGO BUE T 7' IVE plw M ML/ 4 7TOHNEYS June 13, 1967 H.BUETTNER 3,324,789

APPARATUS FOR ST RAPPING PACKAGES Filed Jan. 5,, 1966 G $heets-$heet 2INVENTOR HUGU BUETT/VER A TTORNEYS June 13, 1967 H. BUETTNER APPARATUSFOR STRAPPING PACKAGES Sheets-Sheet :7

Filed Jan.

HVVE/V TOR HUGO BUETT/Vfl? vile MM ATTORNEYS June 13, 1967 v H. BUETTNER3,324,789

APPARATUS FOR STRAPPING PACKAGES Filed Jan. 5, 1966 v 6 Sheets-SheetINVENTOR HUGO BUETT/VER BY I.

A TTORNEYS June 13, 1967 H. BUETTNER 3,324,789

APPARATUS FOR STRAPPING PACKAGES Filed Jan. 5, 1966 6 Sheets-Sheet 5INVE/V TOR HUGU EUETT/VEI? M MM Q/ A TTORMEXS June 13, 1967 Filed Jan.5, 1966 H. BUETTNER 3,324,789

APPARATUS FOR STRAPPING PACKAGES 6 Sheets$heet 6 l/VVE/VTOR HUGO BUE T TIVER Br I m M M 1- 4 4 TTOR/VEY United States Patent 3,324,789AE'PARATUS FOR STRAPPING PACKAGES Hugo Buettner, Gruiten, Rhineland,Germany, assignor to Ampag G.m.b.H. 8; 0mpany KG. Fiied 52111. 5, 1955,Ser. No. 518,939 Claims priority, application Germany, Jan. 9, 1365, A43,085, A 48438,; Feb. 5, 1965, A 48,330 12 Claims. (Cl. 100-27) Thisinvention relates to apparatus for tying packages and, moreparticularly, is concerned with an automatic or semi-automatic strappingmachine for tying packages with a textile or plastic strap.

According to the prior art, automatic or semi-automatic strappingmachines for packages are known where the strap unwinds from a drumpositioned on a rotatable ring. In these arrangements, the package to betied is inserted and supported at a location encircled by the ring withthe free end of the tape being held by a free end gripper located at aposition ahead of the strap sealing device. The ring is then driventhrough a full revolution about the package to wrap the strap into atight loop configuration having opposite strap ends superposed forsealing. Until the time of the present invention, it has been diflicultto assure high speed operation of the rotary ring with packages ofdifferent types and configurations and it has been diflicult to providea reliable arrangement for overlapping the strap ends prior to sealing.

In effecting high speed machine operation, the guiding ring isaccelerated abruptly at the beginning of the loop and is stoppedabruptly at the end of the loop. This rapid acceleration, the resultanthigh circumferential speed and the rapid deceleration acts upon thestrap being unwound from the drum, tends to develop free Wheeling of thedrum upon stoppage of the ring and subjects the strap to jerking forcesand undesirably high tension. In addition, it is more difficult toassure alignment and superposition of the strap at opposite ends of theloop.

In the practice of the present invention, the supply drum from which thestrap is fed as the drum moves around the package with the ring is actedupon by a brake arrangement to respond to increasing tension on thestrap to reduce its holding function or even to eliminate it. As thestrap leads from the drum, it is guided over one or more tension rollerscarried on a spring loaded lever that applies a braking effect upon thedrum. The tension buildup in the strap, acting through the rollers,shifts the lever against the spring action to reduce the brake effect.Initial shifting of the brake lever by strap tension effects directdrive of the drum in a sense to start the drum rotating in its unwindingdirecting. This avoids development of jerking actions and high tensionforces in the strap.

More specifically, the invention provides for guiding and unwinding thestrap from the payout drum like a block and tackle over several idlerrollers that ride directly upon the guiding ring and over one or moreloose rollers that ride on the pivotally mounted brake lever. Severalstorage loops of strap extend between these sets of rollers. In thisWay, comparatively small strap tension values can effect the desiredpivoting of the brake lever in order to reduce the braking effect. Inthis configuration, in the beginning of a strapping cycle there is slackstrap available in the multi-roller system and ready for immediatepayout. Additional slack strap for convenient initial payout isaccommodated by providing a separate floating roller movable against alight spring over a relatively long path in the circumferentialdirection of the rotatable ring. Any excess of unwound strap isimmediately taken up by the action of this roller in the event the ringis stopped suddenly.

An important feature provided in accordance with the practice of theinvention is the use of a movable gripper Patented June 13, 1967 whichis inactive when the strap is being wrapped into a loop while held inthe free end gripper during the rotation of the ring. This movablegripper catches the strap at the feed end of the loop and is operableafter the strap loop has been formed by the ring movement to effectfinal tensioning and alignment of the strap ends in superposedrelationship to facilitate final sealing. In a particular movablegripper disclosed herein, the gripper is guided for movement in theplane of the loop of strap, with the gripper first moving slightly awayfrom the package and then moving in a strap tensioning direction andthen returning to adjacent the package to bring the strap ends intosuperposed relation. The movable gripper carries a cooperating clampingjaw that is operable to clamp the strap against a projecting nose on thegripper, the clamping jaw being actuated during displacement movement ofthe gripper by means of a stationary stop located in the grippermovement path. A sealer unit is timed to operate When the movablegripper brings the strap into overlapping relation.

The movable gripper also carries a knife for cutting off the supply endof the strap, the knife being actuated by a stationary stop in responseto final movement of the gripper. In the strap cutting operation, oneface of the projecting nose of the gripper nests against the strap loopwhile the supply section of strap is held against an opposite face ofthe nose to be cut through by the knife.

Upon completion and cutting of the strapping, the movable gripperreturns to its original position and in so doing transports the newlyformed free end of the strap into the free end gripper, with theoperating lever for the clamping jaw thereafter engaging a stationarystop to free the strap end from the movable gripper in preparation forthe next cycle of operation. The gripper movement as disclosed herein isguided by driving the gripper through a rod system which can be raised,lowered and displaced horizontally to execute the required grippermovement path.

One important advantage of the movable gripper arrangement for holding,guiding and overlapping the strap ends resides in the fact that thesealer unit may remain stationary. Any conventional type of sealer maybe employed and in any event the actual sealer design will besimplified. In particular, where the sealer employs wrap around seals,feeding of the seals and the operation of the sealer jaws for applyingthe seals is facilitated where the sealer unit is stationary.

A further aspect of the invention relates to a rotating ring machinearranged to provide a package with a strap loop not only in one plane,but to form a second loop in a manner analogous to that in hand tyingwhich embraces the package in a second plane perpendicular to the first.The invention provides for forming a single length of strap into amulti-l oop crosstie configuration requiring only a single seal. Forthis purpose, the rotating ring strapping machine is provided withdeflection lever movable into the motion path of the feed end of thestrap to deflect the same to the side of the sealing unit. When theguide ring for the strap comes to a stop after forming a first loop, thepackage is turned by and a further loop is formed in a plane at rightangles. When the final strap loop is formed the deflection lever is inretracted position so that the feed end of the final loop of strap isbrought into the sealer unit in overlapping relation with the free endof the first loop of strap.

The deflection lever may be selectively controlled to enable more thanone strap loop to be formed in the first plane. In this event, thedeflection lever will act at the end of each such loop and the packagewill then be turned 90 for information of one or more loops in atransverse plane, with the final loop being formed while the deflectionlever is retracted to allow overlapping 3 of the start of the strap withthe end of the strap in preparation for sealing.

Instead of guiding the package past the sealing unit for actuation ofthe deflection lever it is also contemplated temporarily to withdraw thesealing unit from the strap loop and after turning of the package,returning the sealing unit to receive the finish end of the final loopof strap.

Other features and advantages of the invention will be apparent from thefollowing description and claims and are illustrated in the accompanyingdrawings which show structure embodying preferred features of thepresent invention and the principles thereof, and what is now consideredto be the best mode in which to apply these principles.

In the accompanying drawings forming a part of the specification, and inwhich like numerals are employed to designate like parts throughout thesame:

FIG. 1 is a front elevational view of a rotary guide ring strappingmachine incorporating features in accordance with this invention;

FIG. 2 is an enlarged fragmentary elevational view illustrating aportion of the guide ring, a strap supply drum mounted thereon and astrap guiding and braking mechanism associated with the ring and drum;

FIG. 3 is a detailed sectional view of the drum and shows a brake leverpivotally mounted thereon;

FIG. 4 is an axial sectional view through the supply drum equipped witha pivotal brake lever shown in elevation;

FIGS. 5-8 are rear elevational views illustrating the strapping machineas a whole with portions thereof broken out to facilitate disclosure andwith the successive views showing various positions in the operatingsequence of a movable gripper;

FIG. 9 is a fragmentary enlarged elevational view further illustratingthe movable gripper utilized in accordance with this invention;

FIG. 10 is a related and greatly enlarged view of the movable gripper toshow it in approximately natural size;

FIG. 11 is a side elevational view of the gripper structure that isshown in FIG. 10;

FIG. 12 is a reduced transverse section through a rotating ringstrapping machine illustrating a pivotally mounted deflection lever usedfor offsetting the feed end of a strap loop, with the lever shown inretracted position;

FIG. 13 corresponds to FIG. 12 and shows the lever in an' advancedposition for deflecting the feed end of the strap; and

FIG. 14 is a related transverse cross sectional view illustrating thelever in retracted position during formation of a final strap loop in aplane perpendicular to the plane of the first strap loop.

Referring now to the drawings and particularly to FIG. 1 thereof, themachine is designated in its entirety at and it comprises main housingstructure including a sectional working table 21 bordering a centralopening 22 which receives the package P to be tied with strapping. Aguide ring 23 is disposed within the housing of the machine 20 toencircle the package opening 22. The guide ring being supported on apair of upper idler rollers 24 and a pair of lower drive rollers 25,which propel the ring 23 in the direction of the arrow in FIG. 1. Atthis point, it should be noted that whereas FIG. 1 is a frontelevational view, FIGS. 5-8 are rear elevational views and the ringrotation appears counterclockwise in FIG. 1 and clockwise in FIGS. 5-8.

A foot switch 26 is shown in FIGS. 1 and 12-14 to effect turn-on andturn-off of a motor 27 that operates the drive rollers to rotate thering v23 at high speed. A strap storage drum 28 is rotatably mountedoutboard of the ring 23 by means of a bracket 29 (FIGS. 2 and 4). Thus,the strap drum 28 rides with the ring and unwinds to payout strap beingwrapped about the package P.

4 The work table, as best seen in FIGS. 12-14, is divided into front andrear sections 21F and 21R to define a strap access way 21W in the planeof the strap loop.

Gripper facilities 30 for the free end of the strap are shown in FIG. 9and normally underlie the work table and intercept the plane of theaccess way to receive and hold the free end of the strap until sealingand severing of the loop is completed. The gripper jaws 30 open andretract laterally to permit another free strap end to be moved intoposition, with the gripper jaws 3t returning to seize the new free strapend. Mechanism for controlling the free end gripper jaws 30 may be ofany suitable type and is preferably integrated with the main power driveand control for the machine to be operated in automatically timedrelation to the remaining mechanisms described herein.

The mechanism for controlling strap feed from the supply drum during thewrapping motion of the rotating ring is best shown in FIGS. 2, 3 and 4.The strap S as it leads from the drum 28 first runs over a movablymounted idler roller 31 carried at the free end of a lever 32 which ispivoted about an axis 32A located outboard of the ring periphery asdetermined by a stationary support arm 33. A slack take up spring 34reacts between the ring .23 and the lever 32 normally to pull the roller31 farther away from the supply drum 28.

In the particular embodiment illustrated herein, a set of four guiderollers 35 are rotatably carried by the ring in generally peripherallyspaced relation and a cooperating pair of guide rollers 36 are carriedon an extension arm 37A of a brake lever 37 which is mounted forrotation about the axis of the supply drum 28. The strap S is threadedback and forth between the rollers 35 and 36 to form a pair of storageloops of strap which apply strap tension forces in a direction to pivotthe brake lever 37 clockwise as viewed in FIG. 2 against the action ofthe load spring 38 that normally biases the brake lever towards aposition to apply brakin action against the drum. Thus, generallyspeaking, an increase in strap tension produces a decreased brakingeffect as is explained in more detail hereinafter.

The brake drum 28 is mounted to rotate on a shaft 39 that is fixedlycarried by the outboard bracket 29. A pair of bearings 39B mount thesleeve portion of the drum for axial and rotary movement relative to theshaft 39. The drum end flange 28F is adjacent to the brake lever 37 andis provided with a friction ring 28R and correspondingly the brake lever37 is provided with a mating friction ring 37R to engage the ring 28Rfor applying brake action on the drum. A compression spring 40 encirclesthe outboard end of the shaft 39 normally to bias the drum ring 28Rtowards the barake ring 37R. In the illustrated arrangement, thecompression effect of the spring 40 is adjustable by varying the numberof insert rings 41 on the outer end of t-he shaft 39, thereby varyingthe axial loading on the drum 23. A replaceable cap screw 42 retains thespring 40. An unloader spring 43 reacts against a fixed flange 39Fimmediately along the shaft 39 and at its other end acts against amounting hub portion 37H of the brake lever normally to tend to separatethe rings 28R and 37R. The bracket 29 is suitably socketed to mount aset of spacer balls 44 which cooperatively bear upon a cam ring 45 thatis mounted on the brake lever 37. As illustrated in FIG. 4, the spacerballs 44 are riding against upraised flat regions on the cam ring 45. Aseries of recesses 45R are provided in the cam ring to receive thespacer balls 29 upon appropriate rotation of the brake lever 37.

When the spacer balls 44 act against the upraised fiat regions of thecam ring 45, pictured in FIG. 4, the braking force exerted on the supplydrum 28 by the coacting friction rings 28R and 37R is a maximum and isdetermined by the spring 40 and by the number of insert rings 41. Whenthe brake lever 37 rotates to receive the spacer balls 44 in therecesses 45R the unloader spring 43 shifts the brake lever 37 while theshaft flange 39F restrains further axial movement of the drum 28 toreduce the engagement of the brake rings and free the supply drum foreasy payout of strap.

According to the invention, the shifting movement of the brake lever isdetermined by the tension in the strap storage loops existing betweenthe rollers 35 and 36. When the tension in the strap increases, thesestrap storage loops tend to pivot the brake lever clockwise as viewed inFIG. 2 against the action of the spring 38. When this pivoting movementof the brake lever brings the spacer balls 44 into the cam ringrecesses, the brake lever 37 is shifted towards the left as viewed inFIG. 4 to reduce or totally eliminate the braking action. It will benoted that the cam ring 45 is mounted to the brake lever 37 by means ofscrews 46 operating in arcuate slots 375 (see FIG. 3) to enableadjustment of the rotary position of the brake lever and hence of thelength of the strap storage loops.

When the guide ring 23 is initially accelerated from the FIG. 1 positionwherein the strap is already secured in the grippers 30, the straptension increases instantaneously to shift the floating roller 31towards the brake drum against the action of the spring 34.Simultaneously, the strap storage loops between the rollers 35 and 36shorten and pivot the brake lever 37 clockwise as viewed in FIG. 2.Since the brake action is effective during this movement, the drum 28rotates with the pivoting brake lever. Thus, the supply drum 28 isstarted in rotation in the strap unwinding direction by pivotingmovement of the brake lever 37. Rapid and easy initial payout of strapis accomplished from the stored strap and is continued by reason ofstarting the drum rotation by the movement of the brake lever. As thebrake force is reduced or eliminated by the pivoting movement of thebrake lever 37 the continued rotation of the guide ring 23 and thewrapping of the package now allows unwinding of the drum with thetension in the strap being determined primarily by the springs 34 and38.

When the aide ring 23 completes a full revolution and stops abruptly thebrake lever 37 instantaneously returns to its braking position to takeup excess strap and to engage the friction rings 28R and 37R forpreventing free wheeling of the strap supply drum 28. Simultaneously,the movable roller 31 is retracted by the spring 34 also to take up anyexcess strap.

A movable gripper element designated generally at 50 is best disclosedin FIGS. -11, and cooperates with the brake regulated drum 28 in thatthe movable gripper accurately effects final tensioning and alignment ofthe strap ends in superposed relation. The movable gripper 50, receivesthe feed end of a strap loop which has been tightly wrapped about thepackage and makes corrections for any loop alignment variationsassociated with the wrapping action.

The sequence views of FIGS. 5 and 6 indicate that the movable gripper isat the same location after a loop of strap has been wrapped about thepackage, FIG. 6, as when the strap is initially inserted in thestationary gripper in preparation for the wrapping. As the rotating ring23 carries the supply drum 25 beneath the package to complete a fullwrapping cycle with more or less tension acting on the strap dependenton the predetermined machine adjustment, the strap is placed beneath theprojecting nose 51 provided at the upper end of the movable gripper inthe fashion illustrated in FIGS. and 11. At this point the movablegripper assembly moves downwardly from the position of FIG. 6 to theposition of FIGURE 7 and then moves horizontally from the position ofFIGURE 7 to the position of FIGURE 8, this movement pattern beingcontrolled by a rod system illustrated d agrammatically and designatedgenerally at 52 in FIGURES 5-8. The movable gripper 50 initially movesdownwardly sufficiently to clear the gripper jaws 30 and the sealer jawsin preparation for the horizontal travel of the gripper which finallybrings the strap end portions into overlapping relationship.

When the movable gripper reaches the FIGURE '7 position, a clamping jaw53 is forced and held against the underface of the projecting nose 51 toseize the feed end of the strap. Subsequent horizontal and then verticalmovement to the FIGURE 8 position draws the strap more more around thepackage and brings the opposite ends into superposed relationship.

A set of upper and lower sealer jaws 54 and 55, respectively, as bestillustrated in FIG. 9 are provided to form and clamp a seal 56 about thestrap ends after the movable gripper 50 brings them into overlappingrelation beneath and within the seal 56. The sealer unit may be of aknown type wherein the upper jaw 54 is laterally reciproca'ble to effectpick up and delivery of a seal of U- shaped outline. Normally, the upperjaw 54 intercepts the plane of the strap loop and holds the U-shapedseal in preparation for receiving the free end of the strap. The upperjaw remains in this position during the wrapping and tensioning of thestrap loop and while the movable gripper brings the free end of strap upinto the seal 56. The lower jaw is held laterally retracted during thistime to enable entry of the strap ends into the seal and thereafter thelower jaw 55 moves laterally and then upwardly to deform the seal andwrap it in clamping relation about the strap ends before the strap isfinally cut. The mechanism for timing the action of the sealer jaws maybe integrated with the remaining elements and powered from the maindrive system to enable high speed automatic operation.

Other sealer arrangements are also contemplated and other and diiferenttechniques may be employed for effecting the seal. In any case, the sealoperation is facilitated by the action of the movable gripper 59.

In the illustrated embodiment, as best seen in FIGS. 10 and 11, themovable gripper unit 5%} includes a rigid base 57 carrying a pair ofupstanding arms 58 that merge at the top to present the projecting nose51 which terminates in a widened guide wall 59. A cam 60 is pivoted onthis base plate and presents an inclined cam face 60F and a pair ofabutment shoulders 60A and 6013 at peripherally spaced locations. Thecam 60 carries a lever arm extension 61 which is best shown in FIG. 9.The clamping jaw 53 nests between the upstanding arms 58 and carries across bolt 62 adjacent its upper end and having opposite extremitiesprojecting through a matched pair of sloping slots 588 provided in thearms. A spring 63 is connected between the bolt 62 and the base plate 57normally to urge the clamping jaw downwardly to the position illustratedin FIGS. 10 and 11. A transverse bolt 64 is anchored between the lowerends of the arms 58 and extends through a vertical slot 538 provided inthe clamping jaw to guide the clamping jaw through a vertically slopingmovement imparted by rotation of the cam 60. The jaw 53 presents a flatupper end face 53F that moves slopingly upwardly to grip the strapagainst the underside of the projecting nose 51 so that final straptensioning is determined by the movement of the gripper.

The machine is provided with a stationary stop 65 located to interceptthe cam shoulder 056A at an intermediate point along the horizontaltravel path of the movable grippers 50 as illustrated in FIG. 7.Continued horizontal travel to the position of FIG. 9 causes therotation of the cam that actuates the clamping jaw 53 to grip the strap,with the cam then remaining in its FIG. 9 position during subsequenthorizontal and upward travel of the movable gripper 59. During suchupward movement of the gripper 50 with the supply end of the strap, thenose 51 approaches and nests upon the start or free end of the strap toassure alignment of the strap ends in overlapping relation within theseal 56 which is being held in the upper jaw of the sealer unit. Thebottom jaw 55 of the sealer unit is now moved laterally and upwardlytoward the top jaw to fold the seal 56 about the overlapping strap endsin a conventional manner. This completes the strap loop and now itmerely must be separated from the strap supply.

A cutting knife 66 is mounted alongside one of the upstanding arms 58 ofthe movable gripper 50 by means of a pivot pin 67 which extends throughthese arms and is engaged by a bias spring 68 anchored to the base plate57 normally to hold the knife 66 in the position illustrated in FIGS.and 11. The knife 66 presents a cutting edge 6 6E arranged to sever thesupply strap end after the seal 56 is applied under the control of anoperating mechanism which is not shown and which is automaticallycontrolled from the main power drive of the machine. A stop 665 is shownin FIG. 9 for actuating the knife 66 at the top of the upward stroke ofthe movable gripper. The widened guide wall 59 coacts with the cuttingedge upon pivoting movement of the knife to accomplish severing of thestrap end for freeing the package from the strap supply.

At this point, the tied package may be removed and it is to be notedthat the newly formed free strap end is still gripped between theclamping jaw and the projecting nose 51 of the movable gripper. Themovable gripper 50 is then actuated to retrace its movement path byfirst shifting downwardly, then horizontally and then upwardly to itsstart position. The free end gripper jaws 30 which were previouslyretracted from the plane of the strap loop now return to seize the freestrap end during the approach of the movable gripper 50 to its startposition. At this time, the abutment shoulder 603 on the cam strikes astationary stop 67 provided in the reverse path of the movable gripperto return the cam and enable the bias spring 63 to retract the clampingjaw 53.

An important advantage associated with the action of the movable gripperSt in aligning and tensioning the ends of the strap loop resides in thefact that the precise position of the supply drum 28 at the end of astrap wrapping cycle is not critical. For example, it is not necessarythat the supply drum 28 be stopped exactly in the hori- Zontal plane ofthe work table 21. It may be slightly above or slightly below the planeas the movable gripper will see to the proper overlapping of the ends ofthe loop. If the guide ring 23 is operated at high speed during thestrap wrapping cycle and suddenly stopped it is diflicult to assureprecise final positioning of the supply drum. The action of the movablegripper in determining the final loop tension and strap overlaprelationship makes high speed ring travel feasible.

Additional strap guiding mechanism is shown in FIGS. 12-14 to enable themachine to be controlled in a fashion for tying multiple strap loops inperpendicular planes by means of a single length of strap and with theuse of only a single joint. If, at the end of a first strap loopwrapping operation, as already described, it is desired to form a secondloop in a perpendicular plane, the mechanism designated generally at 70in FIGS. 12-14 is rendered operative. The housing of the machine 20incorporates internal support structure 71 underlying the work table 21and including an angle bracket 72 which mounts a solenoid 73 to becontrolled by a front panel mounted switch 74. The armature of thesolenoid drives a link 75 connected to a bell crank 76 pivotally mountedon the angle bracket 72 and having a drive link 77 connecting to thelower end of a vertical deflection lever 78. The deflection lever has anintermediate pivot axis defined by the support structure 71 and in itsretracted position illustrated in FIGS. 12 and 14 it is offset slightlyfrom the plane of the strap loop as generated by normal operation of therotating ring 23 and the movable gripper.

Where a package is to be tied in only a single lane, the deflectionlever 78 is left in this retracted position. However, when a package isto be cross tied by multiple loops in perpendicular planes, the switch74 is actuated to operate the links and bell crank and swing thedeflection lever 78 to the position in FIG. 13 wherein it presents aninclined face intersecting the plane of the strap loop for deflectingthe strap end laterally sufliciently to prevent it from entering thesealer jaws which are not shown in FIGS. 1214. After this first straploop is drawn taut, the guide ring 23 is stopped and the package isturned 90 about a vertical axis. The start switch 26 is again actuatedand a second loop of strap is formed about the package in perpendicularrelation to the first loop. In the meantime, the deflection lever 78 hasbeen retracted so that the end of the final strap loop may be guidedinto the sealer jaws in the usual fashion, there to be in overlappingrelation to the start end of the first strap loop. The return of thedeflection lever to enable completion of the final strap loop in theusual fashion may be controlled manually or automatically prior to orduring the wrapping of the second loop. The sealing of the strap endscan be accomplished without any problem even though they relate to straploops that are oriented in different planes. It will be appreciated thatseveral loops of strap may be formed in the first plane by maintainingthe deflection lever 78 projected, with the package then being turned 90to receive several cross tie loops. Again the deflection lever 78 willbe projected until the final loop is to be formed at which time thedeflection lever is retracted.

Thus, while preferred constructional features of the invention areembodied in the structure illustrated herein, it is to be understoodthat changes and variations may be made by those skilled in the artwithout departing from the spirit and scope of the appended claims.

What is claimed is: v

1. In a package binding mechanism, package support means defining astrap access way, a rotary strap supply drum, first gripping meansadjacent the package support means for gripping a strap end leading fromsaid drum, means for transporting the rotary supply drum along a paththat encircles said strap access way to unwind said drum and form a loopof strap about a package that is disposed on said support means, a braketransportable with and engageable with said drum to resist unwindingthereof, and means transportable with said drum and connected to respondto tension in the strap leading from said drum to reduce braking actionbetween said brake and said drum.

2. In a package binding mechanism in accordance with claim 1 and whereinsaid brake is pivotally mounted adjacent said drum to exert a brakingeffect related to pivot position and said brake having an extending armmounting first roller means, resilient means connected to bias saidbrake towards a pivot position of maximum braking effect, and saidtransporting means mounting second roller means adjacent and spaced fromthe first named roller means to receive strap leading from the drum inan expansible strap storage configuration trained between said rollermeans to apply strap tension in a sense to oppose said resilient means.

3. In a package binding mechanism in accordance with claim 1 and whereinsaid brake is pivotally mounted adjacent to and coaxially with said drumto exert a braking elfect related to pivot position and said brakehaving an extending arm mounting first roller means, resilient meansconnected to bias said brake in a drum Winding relation towards a pivotposition of maximum braking effect, and said transporting means mountingsecond roller means adjacent and spaced from said first roller means toreceive strap leading from the drum in an expansible strap storageconfiguration trained between said roller means to apply strap tensionin a sense to oppose said resilient means and enable increased straptension at the start of drum travel to effect pivoting of the brake forinitiating unwinding movement of the drum.

4. In a package binding mechanism in accordance with claim 2 and whereinsaid transporting means includes said path towards and away from thedrum, with strap leading from said drum and first running about saidfloating roller and then about said first and second roller means, andresilient means connected to bias said floating roller away from saiddrum and against the direction of said path to take up any excessunwound strap.

5. In a package binding mechanism in accordance with claim 1 and whereinsaid transporting means is a rotary guide ring having an outboardbracket equipped with a stationary shaft, bearing means on said shaftand mounting said drum for axial and rotary movement relative to saidshaft, said brake being pivotally mounted on said shaft adjacent an endof said drum located near the bracket, a cam element mounted to rotatewith said brake to react against said bracket and effect axial shiftingof the brake towards said drum end in accordance with the brakeposition, spring means reacting axially between said shaft and said drumto bias the drum end towards engagement with the brake and spring meansreacting axially between said shaft and said brake to bias the brakeaway from the drum end when the cam element permits.

6. In a package tying mechanism, package support means defining a strapaccess way immediately underlying a package located on said supportmeans, sealing means adjacent the strap access way to receive and joinoverlapping strap portions, first gripping means adjacent the strapaccess way for gripping a free end of strap beneath the package todispose a free end strap portion in the sealing means, strap wrappingmeans movable along a path that encircles the strap access way to form aloop of strap about the package, a movable gripper having a noseadjacent the strap access way to catch a feed end strap portion as theloop is being completed by the strap wrapping means, and means formoving the movable gripper to bring the feed end strap portion into overlapping relation to the free end strap portion.

7. In a package tying mechanism in accordance with claim 6 and whereinsaid strap wrapping means includes a rotary strap supply drum presentinga free end of strap engaged in said first gripping means to enableunwinding of said drum to pay out strap as said drum moves along a pathencircling the package, a brake transportable with and engageable withsaid drum to resist unwinding thereof, and means transportable with saiddrum and connected to respond to tension in the strap leading from saiddrum to reduce braking action between said brake and said drum.

8. In a package tying mechanism in accordance with claim 6 and whereinsaid first gripping means is between said sealing means and said movablegripper when the strap wrapping means forms the loop of strap about thepackage and wherein said moving means thereafter transports said movablegripper to a location where the sealing means is between said firstgripping means and said movable gripper.

9. In a package tying mechanism in accordance with claim 8 and whereinsaid moving means includes means for shifting the movable grippergenerally downwardly, then generally horizontally beneath the firstgripping means and the sealing means and then generally upwardly.

10. In a package tying mechanism in accordance with claim 9 and whereinsaid movable gripper has a clamping jaw shiftably mounted thereon andcam means carried on the movable gripper and responsive duringhorizontal movement thereof to actuate the clamping jaw to grip the freeend strap portion against said nose during the remaining movementthereof.

11. In a package tying mechanism in accordance with claim 6 and whereinsaid movable gripper has a clamping jaw shiftably mounted thereon andnormally biased away from said nose, cam means mounted on the movablegripper to actuate said jaw to grip strap against the nose, and a knifemounted on the gripper to sever strap held between said nose and jaw,and wherein said moving means reversibly shifts said movable gripperalong a travel path between a loop wrapping position and a loop sealingposition, said travel path leading generally downwardly, then generallyhorizontally and then generally upwardly, said first gripping meansbeing between said sealing means and said loop wrapping position for themovable gripper and said sealing means being between said first grippingmeans and said loop sealing position for the gripper, and wherein afirst stationary stop activates the cam means when the gripper isintermediate along its horizontal motion, a second stationary stopactivates the knife as the movable gripper arrives at the sealingposition, and a third stationary stop deactivates the cam means when themovable gripper arrives back at the wrapping position to free the newstrap end to be held by said first gripping means.

12. In a package tying mechanism, package support means providing astrap access way immediately underlying a package located on saidsupport means, sealing means adjacent the strap access way to receiveand join overlapping strap portions, gripping means adjacent the strapaccess way for gripping a free end of strap beneath the package todispose a free end strap portion in the sealing means, strap wrappingmeans movable along a path that encircles the strap access way to form aloop of strap about the package, a deflection lever adjacent the sealingmeans and active at an advanced position to deflect a feed end strapportion as the loop is being completed by the strap wrapping means, saidsealing means and gripping means being stationary and cooperably holdingthe free end strap portion while the package is turned to rotate thefirst loop about means for shifting the deflection lever to a retractedposition, and means for reactuating the strap wrapping means to formanother loop of strap about the turned package to bring a feed end strapportion into the sealing means in overlapping relation to the free endstrap portion.

References Cited UNITED STATES PATENTS 2,467,286 4/1949 Young et al.53-203 2,469,544 5/1949 Bunn -27 2,608,150 8/1952 Cranston 100-272,614,487 10/1952 Cheesman 10027 2,696,778 12/1954 Ervin 10027 2,748,6926/1956 Osgood et al. 10027 2,972,844 2/1961 Ripley 53198 3,126,6863/1964 Kobylanski 53-198 3,247,781 4/ 1966 Meckler 10027 BILLY IWILHITE, Primary Examiner.

1. IN A PACKAGE BINDING MECHANISM, PACKAGE SUPPORT MEANS DEFINING ASTRAP ACCESS WAY, A ROTARY STRAP SUPPLY DRUM, FIRST GRIPPING MEANSADJACENT THE PACKAGE SUPPORT MEANS FOR GRIPPING A STRAP END LEADING FROMSAID DRUM, MEANS FOR TRANSPORTING THE ROTARY SUPPLY DRUM ALONG A PATHTHAT ENCIRCLES SAID STRAP ACCESS WAY TO UNWIND SAID DRUM AND FORM A LOOPOF STRAP ABOUT A PACKAGE THAT IS DISPOSED ON SAID SUPPORT MEANS, A BRAKETRANSPORTABLE WITH AND ENGAGEABLE WITH SAID DRUM TO RESIST UNWINDINGTHEREOF, AND MEANS TRANSPORTABLE WITH SAID DRUM AND CONNECTED TO RESPONDTO TENSION IN THE STRAP LEADING FROM SAID DRUM TO REDUCE BRAKING ACTIONBETWEEN SAID BRAKE AND SAID DRUM.